In the Linux kernel, the following vulnerability has been resolved: rtnetlink: add missing netlink_ns_capable() check for peer netns rtnl_newlink() lacks a CAP_NET_ADMIN capability check on the peer network namespace when creating paired devices (veth, vxcan, netkit). This allows an unprivileged user with a user namespace to create interfaces in arbitrary network namespaces, including init_net. Add a netlink_ns_capable() check for CAP_NET_ADMIN in the peer namespace before allowing device creation to proceed.
https://git.kernel.org/stable/c/d04cc16d3624218a5458b2b664ae431f1b3b334d
https://git.kernel.org/stable/c/7b735ef81286007794a227ce2539419479c02a5f
https://git.kernel.org/stable/c/0975b64ffb34560042090a5986c3a02e6c80f36f